Theories for interventions to reduce physical and verbal abuse: A mixed methods review of the health and social care literature to inform future maternity care

Despite global attention, physical and verbal abuse remains prevalent in maternity and newborn healthcare. We aimed to establish theoretical principles for interventions to reduce such abuse. We undertook a mixed methods systematic review of health and social care literature (MEDLINE, SocINDEX, Global Index Medicus, CINAHL, Cochrane Library, Sept 29th 2020 and March 22nd 2022: no date or language restrictions). Papers that included theory were analysed narratively. Those with suitable outcome measures were meta-analysed. We used convergence results synthesis to integrate findings. In September 2020, 193 papers were retained (17,628 hits). 154 provided theoretical explanations; 38 were controlled studies. The update generated 39 studies (2695 hits), plus five from reference lists (12 controlled studies). A wide range of explicit and implicit theories were proposed. Eleven non-maternity controlled studies could be meta-analysed, but only for physical restraint, showing little intervention effect. Most interventions were multi-component. Synthesis suggests that a combination of systems level and behavioural change models might be effective. The maternity intervention studies could all be mapped to this approach. Two particular adverse contexts emerged; social normalisation of violence across the socio-ecological system, especially for ‘othered’ groups; and the belief that mistreatment is necessary to minimise clinical harm. The ethos and therefore the expression of mistreatment at each level of the system is moderated by the individuals who enact the system, through what they feel they can control, what is socially normal, and what benefits them in that context. Interventions to reduce verbal and physical abuse in maternity care should be locally tailored, and informed by theories encompassing all socio-ecological levels, and the psychological and emotional responses of individuals working within them. Attention should be paid to social normalisation of violence against ‘othered’ groups, and to the belief that intrapartum maternal mistreatment can optimise safe outcomes.


Introduction
In 2010, Bowser and Hill published a landscape analysis reporting on disrespect and abuse of women during childbirth [1]. In 2015, WHO published a review that classified disrespect and abuse into seven domains, under the overall typology of 'mistreatment during childbirth' [2]. These domains include verbal and physical abuse. Since the publication of these papers, there has been increasing evidence in this field, relating to both women and newborns [3][4][5]. As a result, efforts to improve maternal health are now focused on improving quality of both the provision and experience of maternity services as a critical component of Universal Health Coverage (UHC), particularly in LMIC settings. The current WHO recommendations on maternity care for a positive childbirth experience [6-8] emphasize the overarching importance of respectful maternity care. This includes the need for staff and health services to create enabling maternity environments to encourage a woman's sense of control and their involvement in decision-making. Improving experiences of women during maternity care requires both promotion of respectful care, and reduction of mistreatment [1,2]. In 2018, a systematic review of controlled studies undertaken in low-income settings and designed to increase respectful care was undertaken by some of the authors of the current review [9]. The findings indicated that multifactored approaches to increase respectful care could work in low-income settings. Based on the three findings with moderate confidence, we concluded that effective implementation to increase respectful care requires: . . . a visible, sustained, and participatory intervention process, with committed facility leadership, management support, and staff engagement. It is still unclear precisely which elements of a package of RMC [respectful maternity care] implementation might be most successful, and most sustained over time. . ..
As part of the move to promote respectful care, WHO has been working on improving the evidence globally in relation to measuring the prevalence of mistreatment of women during childbirth and raising awareness for evidence and action [10]. In 2019 the team published a paper reporting on a prospective cross-sectional study of women from admission in labour and up to two hours postpartum in twelve facilities across four countries (Ghana, Guinea, Myanmar, and Nigeria) [11]. Some degree of physical or verbal abuse or stigma/discrimination was observed in 838 (41�6%) of 2016 women, and reported by 945 (range 4-35% by facility) of those surveyed after their birth. Physical and verbal abuse was particularly prevalent in the half hour before birth and the 15 minutes afterwards, and verbal abuse was more likely to be experienced by younger than older women (�30 years), adjusting for marital status and parity [11]. These findings suggest that little had changed in the ten years since Bowser and Hill first highlighted the issue of abuse in maternity care, despite a significant increase in studies in this area. Looking beyond the reproductive health literature may provide new insights for future effective interventions.
Issues of mistreatment have been identified in other health and social care fields [12]. In particular, there is a body of literature on de-implementation of inappropriate use of physical and pharmacological restraint in nursing and residential services [13], that mirrors current debates about use of unnecessary or unconsented physical and pharmacological interventions in maternity care. Indeed, use of physical restraint on women using maternity services has been reported most recently in 2020 [14,15].
Although there may be some particular drivers for mistreatment in maternity care (including gender based inequalities, and social norms about desirable reproduction and undesirable reproduction) most underlying factors for mistreatment of service users in health and social care are likely to be similar across disciplines. To date, however, there have been no studies that explore the issue of mistreatment in general, and verbal and physical abuse in particular, in a cross-disciplinary review.
This paper reports on a mixed-methods systematic review of theoretical insights into what might underpin verbal and/or physical abuse in health and social care in general, and of interventions designed to reduce such abuse, with the aim of identifying candidate theories for designing future intervention studies. The findings are synthesised to generate hypotheses about the optimal theoretical underpinning for future implementation of change in this area, and the synthesis is then mapped to published intervention studies in maternity care.

Aim
To establish theoretical principles and mechanisms of what works in reducing physical and verbal abuse in health and social care, as a basis for designing effective interventions for maternity services in the future. 1. What theoretical explanations have been proposed to explain drivers for and/or prevention of physical and verbal mistreatment by professional health and social care providers?

Research questions
2. What interventions are effective, feasible and acceptable for reducing physical and/or verbal mistreatment of service users by professional providers of health and social care, when compared to usual care, or to alternative interventions?
3. What kinds of theoretically informed interventions work, or might work, in a range of contexts, to reduce physical and verbal abuse of childbearing women by health care providers?

Definitions
We used the following definitions of physical and verbal abuse, adapted from the Bohren [2] typology of mistreatment of women during childbirth, with additional terms that are relevant to other areas of health and social care, based on the results of our initial scoping review: Verbal abuse Harsh or rude language; shouting, insults, scolding, mocking; judgemental or accusatory comments; threats of withholding treatment or of using unnecessary treatment, or of poor outcomes; blaming for current situation, or current or potential future poor outcomes.

Physical abuse
Being beaten, slapped, kicked, punched, or pinched; physical restraint; gagged; physically tied down; (childbearing women: forceful downward pressure); rough use of instruments or interventions.
Register of Controlled Trials (CENTRAL) (Cochrane Library). Given the high yield of results retrieved in these databases, and potential overlap of content, the decision was made not to expand the search to further databases originally considered in the protocol. No date or language limits were applied to the search. The search was updated on March 22 nd 2022. The full search strategy for the Medline database (Ovid platform) is provided in S1 Table. A log was set up to record hits and numbers of included papers at each stage of selection. One member of the review team (CH) undertook the searches in each database and carried out de-duplication. The de-duplicated results were imported into Rayyan for screening.

Study selection
At the title and abstract stage of both searches regular meetings were undertaken with the whole team to ensure consistency in decision making. At the full text stage, selection was initially undertaken in three pairs. Calibration exercises were conducted within each pair, where screeners independently screened 100 hits in batches until an 80% level of agreement was reached within the pair. Where sufficient agreement was not reached after the first 100 hits because of areas of uncertainty, this was discussed in the wider team, and the inclusion process was refined by consensus. This process continued until sufficient agreement was achieved. The remaining studies were then screened by four members of the review team (RN, AF, LG, HM) independently for the index search, and by SD and HM in the updated search, with consultation between team members where decisions could not be easily made. Studies in languages that could not be translated sufficiently by the author team, google translate, or other contributors were logged but not included in the analysis.
As the selection process proceeded, it became apparent that there are a very large number of studies and papers focused on restraint and seclusion in psychiatric care. It was not always easy to determine if the issue was about therapeutic methods of restraint, or about restraint as abuse. To avoid overwhelming the review with papers from this very specific field, the decision was made to exclude papers on seclusion (as this was not deemed to be either verbal or physical abuse) and also to exclude those on medication in psychiatric settings as a means of restraint. We also excluded mechanical restraint in these settings, though we did retain papers on mechanical restraint in critical illness settings, as these were agreed to be more like the kinds of settings in which such restraint might be used in maternity care. For example, women in labour may be mechanically restrained if they have had a sedative (to prevent falls), or their movement may be constrained by IV lines, lithotomy, or wired fetal monitoring machines. See Table 1 for inclusion and exclusion criteria.
The intervention design and outcomes of controlled intervention studies in maternity care published since our previous systematic review of such studies [9] were tabulated and assessed against the synthesised theoretical framework of the current review, to establish the extent to which these interventions have been aligned, or not, to the findings of the review.
Studies and papers based in maternity care settings that included implicit or explicit theory were, however, included in the primary theoretical analysis.

Quality assessment
Risk of bias ratings were applied to studies included in the meta-analysis [16] There is no quality assessment tool for theoretical data, and, indeed, epistemologically this would not be relevant. Though the protocol stated that quality assessment would be undertaken for qualitative studies, it was decided in the team that this was not required, since the findings were not the unit of analysis: the issue of interest was the explicit and implicit theories that were evident in the included studies.

Record of study characteristics
For the research studies and articles including theoretical concepts, relevant data from all included full-text studies were logged on a study-specific data capture form. This included the bibliographic details, and characteristics of included papers; aim of study, participant characteristics (where relevant) implicit, explicit theories, other explanations of mistreatment; and findings from research papers. The form also captured the health/social care domain(s) of each paper, and the type of mistreatment that was addressed.
For the controlled studies, data were extracted using a pre-piloted form by one reviewer and checked by a second reviewer. Disagreements were discussed between reviewers and, if consensus was not achieved, arbitration was carried out by a third reviewer. We extracted data on the citation details, country of study, study design, data collection method, primary outcome, secondary outcomes, intervention, underpinning theory, setting, type of mistreatment, participants characteristics, primary and secondary outcomes, and methods of data collection and analysis.

Studies including theory
We intended to undertake an adaptation of the meta-narrative approach [17] to track theories used by different disciplines over time and to create an initial taxonomy of candidate theories that could underpin intervention studies to reduce physical and verbal abuse. In the event, very few studies included formal underpinning theory, so this analysis could not be undertaken. Our approach was to identify author-identified ('explicit') a-priori or post-hoc theories cited in the studies and to identify sections of the text of the included papers that referred to implicit or explicit theoretical concepts or models, or drivers for verbal or physical mistreatment. Both explicit and implicit theories were logged. We summarised these findings narratively.
Controlled intervention studies. Our outcome of interest was any reduction in any measure of physical or verbal abuse (primary). We also looked for information on the acceptability of the intervention(s) for staff or service users, fidelity to the protocol, and for any evidence of sustainability.
RCT and before and after ('controlled') intervention studies that had measures of relevance to the review were logged. Where possible, meta-analysis was undertaken to assess the effectiveness of the intervention. We pooled studies through the inverse variance method, estimating the standardised mean difference (SMD) with 95% confidence intervals, using random effects models.
Heterogeneity was assessed through visual inspection of the forest plots and the I 2 statistic. Pre-specified sub-group analyses were produced, focusing on study design, underpinning theory, care setting, people receiving the intervention, type of intervention and country income level. Sensitivity analyses explored the effects of different studies on the outcomes.
We also intended to use network meta-analysis techniques [18], if the data were robust enough, to identify pathways that stood out as highly influential, or contexts that tended to be associated with the success or otherwise of particular theories. In the event, this was not possible due to insufficient data of adequate precision to develop an evidence network.

Synthesis and logic model
We used a results-based convergent synthesis to integrate the findings across the papers with theoretical elements and intervention studies [19], as a means of answering our third research question. This approach is defined by Hong as: where qualitative and quantitative evidence is analyzed separately using different synthesis methods and results of both syntheses are integrated during a final synthesis [19]. The synthesis was intended to illuminate what fundamental theoretical approach(es) might have most utility as a basis for designing interventions to reduce physical or verbal mistreatment in a range of contexts. We then mapped the resulting model to controlled studies in maternity service provision to assess the extent to which our model is reflected currently in interventions used in controlled studies designed to reduce verbal and/or physical abuse in maternity care. Finally, we created a logic model as the basis for hypotheses about critical contexts and mechanisms of effect arising from our findings.

Changes from protocol
Changes from the protocol are described above.

Results
In the primary search (2020), a total of 23,699 studies were identified from the database searches. Following de-duplication 17,628 were retained for screening. Screening on title/ abstract revealed 693 relevant studies for full text review. Many of these were focused on physical restraint in a range of settings. Ninety of them required inter-library loan requests, and a decision was made to only pursue a sub-set that were intervention studies, or that were not physical restraint studies (n = 24). Eleven of these could not be sourced, leaving 616 for full text screening selection. During full text screening it became apparent that a very large proportion of the remaining studies meeting the inclusion criteria were also focused on physical restraint. At that point, it was decided that the remaining physical restraint papers would be excluded, unless they were intervention studies, or studies with a strong theoretical basis. During closer scrutiny by the quantitative team, thirteen of the RCT or before and after studies of restraint did not have identifiable point estimate measures of restraint use, and so these were also excluded. Ninety-eight of 150 physical restraint papers were therefore excluded at this stage. A further 324 papers were excluded for a range of reasons (Fig 1).
The remaining 193 included papers were grouped into those including theoretical components (n = 154 [20-173]) (qualitative and quantitative and reviews) and (n = 39 ) non-maternity controlled intervention studies with at least one outcome measure of verbal or physical abuse.
In the updated inclusion decision process, we did not check for primary papers included in the previously published reviews that had not been identified by our search, given that the primary papers in the previous reviews were not selected for their theoretical content. However,

PLOS GLOBAL PUBLIC HEALTH
Theories for interventions to reduce physical and verbal abuse in maternity care we did check to ensure there was no substantial overlap between the papers contributing to the previous reviews and our primary theory papers, to avoid 'double weighting' of the overall contribution of the prior reviews to our analysis.
The three included reviews of controlled studies [242,245,252] and two of the primary controlled papers [243,244] also included some theory. They are included in the analysis of theory papers, resulting in a total of 34 papers with theoretical components. The results of both searches are combined in the rest of this paper.
The following section expands on the theories listed in Table 2.

Maternity studies (n = 58)
About half of the maternity papers mentioned explicit theories. , in which the risk of being judged "abnormal" by others is internalized, making powerful norms work from within, and Foucaults theories of power/ resistance to power [225]; and Jacobson's taxonomy of dignity [88], and learned helplessness [88]. One paper [159] explored behavioural concepts of mental models, and of 'automaticity' (based on the concept of cognitive availability/scarcity, in which a hegemonous focus on death avoidance left no space for consideration of other aspects of good quality maternity care. Another [160] was framed by the notion of authoritative knowledge, in which the knowledge and beliefs of the most powerful group frame what is acceptable in terms of actions. One paper explicitly cited the socio-ecological theory [236]. Implicit theories used in the maternity studies tend to focus on gender inequalities [43,160], internalised, organisational and social norms around general acceptability of mistreatment [22,39,46,160,217,218,224,226,235] (for example, in the case of the 'difficult' patient, or where the safety of the baby was seen to be at risk) and social/cultural norms about the acceptability and expectation of violence against women (gender-based violence) [22,39,75,157,173], control of deviation from perceived gender/role or stereotype [43], and stigma and shaming around sex (as dirty or sinful) [24,46,157,159]. Vertical transmission of mistreatment was captured in theoretical assumptions that gender inequalities and consequent mistreatment experienced by female staff (including limited access to resources and opportunities) could lead to frustration and burnout and consequently blunted compassionate relating, resulting in mistreatment of women during childbirth and labour.
Some of the theories capture how intersectionality compounds inequalities in both female staff and service users, and in hierarchies within gender (related to class, ethnicity or marital status). From this perspective, assertion of power differentials (from institutionally oppressed health care professionals to socially oppressed service users) results in social sanctioning, and punishment of service users for not following the institutional rules, or for non-payment of fees, as this is a domain over which the staff have control, and the service users do not. Social sanctioning includes restriction of birth companionship to avoid anticipated resistance to rules if the woman has a companion with her, or to minimise external observation of mistreatment.
The relative lack of power of female staff as compared to equivalent male staff is proposed as a reason for finding evidence of greater mistreatment by female midwives/nurses than male health workers in equivalent roles. Power based theories also argue that the struggle to assert the professional status of midwifery/nursing results in preference for over-medicalisation by staff in some contexts, and of strong local norms in which service users are often conceptualised as inferior to staff, socially and morally. In a nuanced take on gender based violence theories, where the gender of the person inflicting abuse was explicitly examined, it was more often attributed to female rather than male staff. Poorly resourced facilities (i.e. resources, workload, skilled staff) and institutional infrastructure (lack of supervision) are repeatedly mentioned across papers, as are institutional norms about mistreatment (e.g. as acceptable practice).
In the index review, there are some differences in emphasis across the dataset. Within African countries, some report on gender based violence (

Physical and verbal abuse in non-maternity studies, other than physical restraint (n = 35)
A few studies in this category include patients in general wards and emergency departments [33,35,71,72,131,158], adults with learning difficulties [64,113], and psychiatric inpatients [86]. However, most identify risk factors associated with mistreatment of elderly persons in residential care [37, 52, 55, 61, 76-78, 89, 94, 121, 128, 136-138, 143-146, 152, 153, 162], highlighting interactions between institutional factors and staff and patient characteristics, rather than proposing theories to explain this, with the exception of two papers. Moore [136] discusses a range of social psychology theories and explores findings using a socioecological framework, proposing that Henri Tajfel's theory on the social psychology of intergroup relations is a useful theoretical model to explain abuse of elderly people in a care home. Natan [138] uses the theoretical model for predicting causes of maltreatment of elderly residents developed by Pillemer [144]. This includes three components of the work environment; patient traits; and the Theory of Reasoned Action developed by Ajzen & Fishbein [256].
One of the papers also mentions exogenous factors [144] such as bed shortage based on local supply and unemployment rates. Another paper [162] on elderly care used the positioning theory in which interactions are conceptualised as being based on individuals taking certain 'positions': clusters of rights and duties to act in certain ways and impose particular meanings, which enable or prohibit access to certain storylines. The medical model of disability is mentioned in a paper about care of women with learning disabilities [113].
More generally, most papers in this area argue that relevant situational factors, including staff burnout, patient-staff conflict, lack of knowledge and/or relational factors impact on mistreatment [61,78,121,128,[144][145][146]. Victim blaming was used as a justification for mistreatment in a number of studies, on the basis that elderly residents were aggressive and abusive, and therefore required a robust physical or verbally response to regain control over the individual and/or the situation [37, 76, 77, 138]. Gender issues were also raised, in that female older adults were noted to be most likely to experience physical abuse [37,131,138,152]. In parallel with the evidence on mistreatment in maternity care when women do not have labour and birth companionship, social isolation was noted to be a relevant factor, particularly for older adults who did not have relatives and friends as protectors, so were deemed to be most likely to experience abuse [37,144].
A conceptual review [257] was referenced in one of the included papers. This was not located in the search for the current study, as it did not include the key words. This review identifies a typology of risk factors for maltreatment, including institutional factors, carer and patient characteristics.
Physical restraint, not in elderly populations or in mental health (n-21). An explicit theory was only mentioned in a few papers in this category. Both Via-Clavero [170] and Perez [142] used the theory of planned behaviour to explain physical restraint use and how to reduce it in intensive care unit settings. The authors discuss the influence of workload pressures on nurses' intention to use physical restraint, and subjective norms and controlling factors that contribute to this, in line with Ajzans theory [256]. Acevedo-Nuevo uses the Iceberg theory noting: 'According to this theory, the visible part of the iceberg represents PR use, but lower down, an intricate network of interrelated elements is at work; here, all health care actors exert an influence on the main actors in PR use (i.e., the nurses) (p3) [213]. Social and organisational normalisation/ of restraint is explicitly referred to in two studies (p78) [231,233]. Smithard notes: For many the use has become institutionalized, with accepted practice hard to change [233].
Staff and external organisational risk aversion [242] and labelling theory (related to victim blaming) [237] also feature in this group of studies.
Implicitly, notions of institutional norms to protect patient safety are particularly evident in the studies in the intensive/critical care setting, either due to the nature of the procedure or patients' functional ability, centred around preventing interference with tubes and/or to prevent extubation [105, 130,133,142]. Lach notes that Prevention of falls is a primary reason for restraint use on medical-surgical units, whereas preventing removal of medical devices and confusion are primary reasons in critical care settings. [125] In many of these analyses, the point is made that there is evidence that restraint use in these settings does not in fact lead to decreased danger for patients, in direct contrast to nurses beliefs.
In three studies [105,142,242], the concept of risk minimisation is discussed in more depth along with the implications of a blame culture in which nurses have to take on responsibility for decision making in relation to restraint use in critical/acute care. The argument is that this leads to unnecessary or over-use of restraint, for fear of litigation, or of blame within the organisational structure, in line with some of the self-protective theories in maternity care noted above. In this case, the personal consequences of making a decision that is not in line with the risk minimisation focus of the organisation outweighs the risk to the patient, or the professional values of the nurse, leading to a sense of lack of mutual support, and therefore increasing the likelihood of using physical restraint.

Physical abuse or restraint in the elderly (n = 44)
Where explicit theories occurred in this set of papers, they included the use of complexity theory [28], and the theory of self-organisation (practice that emerges based on the interconnectivity between people and how they relate to each other), and related notions of open systems theory [68], in which organisations are influenced by the context and environment they operate in. Approaches also included moral geographies [29] in which moral norms for a particular group are calibrated in relation to the physical proximity of people to each other, and across different geographical spaces, such as private versus public domains. Behavioural change theories featured in two papers [42,241]. Theories of racism [66] were also used, where Black residents were more likely to be abused than White residents. Stereotyping and normalisation of stereotypes, specifically negative beliefs about, and attitudes towards, the social value and status of the elderly were identified [228,232]. Some authors developed their own frameworks of interactions between factors such as organisational, resident functional capacities/behaviour, personal and psychosocial drivers, and physical environment, to examine associations with physical restraint [164,132]. For two authors, these levels of action were formally captured in the socio-ecological model [116,228].
Where theory was implicit, the predominant explanation of the use of physical restraint in elderly population is for patient safety (e.g. to protect patients from falls and prevent injury from wandering). Underlying this ideology of protection of elderly residents is a belief system within institutions that patients are frail and have diminished responsibility and lack autonomy, in parallel with staff fear of litigation or blame by peers and superiors when accidents and injuries do occur. Thus, as in other sections of this review, physical pressure or restraint was used in the belief that it offered protection from adverse physical outcomes for the elderly, and was prioritised over dignity and autonomy, even though this was recognised as dehumanising by some staff.
The consequent disconnect between professional values of care and compassion and the action of enacting physical restraint resulted in moral distress for some staff. Indeed, some papers discussed the need for balance in maintaining physical and psychological integrity, presenting nurses with an ethical dilemma with the use of physical restraints. In this case, underpinning decision-making was the ideology of nursing as a moral practice (particularly Goethals [95]). This is associated with 'doing good' with protecting patients from physical harm and/or maintaining the psychological integrity/safety of other elderly patients.
One review highlighted social and cultural norms as an important influencer of physical restraint by nursing staff, highlighting differences in restraint use between the Netherlands, Germany and Switzerland [114].

Physical restraint in those with mental health issues (n = 30)
Two papers in this group focused on stigma against those with mental health issues [56, 234], Trauma informed care, social learning theory, salutogenesis (ie, the impact of a low Sense of Coherence) all featured in a review undertaken by Perers [253], Other studies related to this topic were more focused on behavioural and psychological theories, including how staff response is stimulated by patient actions [129] and behavioural change theory [240].
Implicit theories were linked to the dilemma between risk minimization and humanization. Organisational barriers to environments that promote on-going support of, and knowledge development in, local practitioners included low levels of staffing and resources. Gender inequalities also featured in some of the discussions, in terms of assumptions about how men and women 'typically' provoke violence, or not.
Another emergent topic in this category was the need for staff to optimize a sense of safety and security within a mental health setting, and consequent risk aversion. The argument is that when there is increased staff exposure to resident or patient aggression, there may also be an increase in the use of restraints, due to a desire for self-preservation by staff [41]. In some cases, nurses acknowledged that while it is not a first line treatment, in situations where no other alternatives exist, restraint is a 'necessary evil' [93].
Although not mentioned as a primary theory, patient-provider communication was found to be an implicit theme in a number of studies in which patients/residents reported that restraint was unnecessarily overused, linking with the over-medicalisation theories in other sections above [56]. In another study, discussion with patients uncovered a desire for communication and collaboration to establish restraint-use alternatives [91].

Papers reporting non-maternity intervention studies (n = 53)
The full characteristics of these papers are given in S4 and S5 Tables. The summary characteristics are provided in Table 3.

Study Setting
In facilities/acute care 3 Care home 10 2 Children's care home 2

Fidelity, acceptability and sustainability
This was assessed for the studies in the updated review. In general, these domains were not well reported. Only one paper cited a protocol [255] but this could not be found on the Chinese Trials Registry, and it isn't clear if the study followed the protocol that was registered.
Chen [246] and Dixon [247] both reported that their tools seemed to be acceptable to staff. Hevener [249] undertook a formal staff audit, and noted that, while the majority of respondents found the intervention tool (the Restraint Decision Wheel) to be useful in principle, they still preferred to use their own judgement in deciding when to restrain a service user.
Sustainability was implied for six studies where time series data were reported [243,244,249,250,251,253], all generally showing maintenance of changes over time.

Effectiveness
For individual studies, comparison of the different interventions with usual care tended to demonstrate positive change in the primary outcomes measured in the intervention arms, or the 'after' phase. However, only 14 studies provided point estimates and measures of variability to enable meta-analysis, and these were all measures of impact on physical restraint [174, 183, 187-188, 191, 193, 194, 196-198, 203, 204, 248, 253]. The characteristics of these studies are provided in Table 4.
Most of the meta-analysed papers do not explicitly mention underlying theory. Some report consultation work to develop guidelines with experts based on the evidence base, but do not mention specifics about the evidence base. Where explicit theory is mentioned, and where theory was implicit, the general approach seems to have been some version of the theory of planned behaviour [262]. Thirteen of the interventions [174, 183, 187, 188, 191, 193, 194, 196-198, 203, 204] were primarily focused on training in alternative strategies so appear to be based on the hypothesis that excessive use of restraint is related to a lack of knowledge about alternatives. Two papers (same study team) [203,204] used mindfulness methods, implying a hypothesis that stress/distress in staff or patients could be a trigger for unnecessary physical restraint

Risk of Bias
Risk of bias was evaluated for all of the studies included in the meta-analysis (See Table 5). Full risk of bias details are in S6 Table.  The assessment revealed some concerns with twelve of the fourteen studies (and all of the RCTs) [174,183,187,191,193,194,196,198,203,204]. The funnel plots also suggest some publication bias, so the results of the meta-analysis should be treated with caution.

Findings
The 14 studies made 15 comparisons. Although two studies presented two comparisons, only one comparison could be included as the other reported no events [188].
The pooled outcome showed a statistically significant beneficial effect in reducing restraint following the different interventions compared to usual care (SMD -0.69 (95% CI: -1.15; -0.24) (Fig 3). Table 5. Summary risk of bias for studies included in the meta-analysis.

PLOS GLOBAL PUBLIC HEALTH
Theories for interventions to reduce physical and verbal abuse in maternity care An intervention that involved both staff and patients had a greater benefit than those focused on staff only [179] (SMD -1.77 (95% CI: -1.82; -1.73)) (Fig 8). Multicomponent interventions seemed to have a larger effect than those based on education alone, but this did not reach statistical significance (SMD -0.37 (95% CI: -0.89-0.15) (Fig 9,. The influence of a country's income could not be assessed as all studies that were suitable for meta-analysis were undertaken in high-income settings. Heterogeneity affected most of the meta-analyses, despite undertaking sub-group and sensitivity analyses (I 2 >90%). Only the sub-group analyses that focused on the RCTs and CCTs, on the education only interventions, and on care and residential home settings reduced the heterogeneity to being unimportant. The occurrence of heterogeneity is unsurprising given the diverse evidence base, where participants, interventions, outcome measures, study designs and setting vary considerably.
Importantly only 14 of the 50 non-maternity controlled studies were included in the metaanalyses. This reflects the lack of data reported in the studies, with many not reporting measures of variability (e.g. standard deviations, confidence intervals), or participant numbers, or outcomes for different groups.

Synthesis
The analysis above indicates that a wide range of implict or explicit theories have been used in studies and papers that address mistreatment, including physical and/or verbal abuse, in health and social care. The theories used tend to focus either on aspects of the health or social care system, or on wider societal and cultural norms, or on the behaviours, norms and attitudes of the individual practitioners working within these systems. Based on these observations, we propose a model that could explain the mechanisms that might trigger and sustain physical and/or verbal abuse (and that therefore could be used for change in future maternity care interventions). The approach is based on an integration of both the social-ecological theory [258,259] and the theory of planned behaviour [256], to capture both systems and people factors.
We propose that this model, or alternatives that integrate both a systems wide and a human factors approach, might be a useful template for formative research. This could be used to identify mechanisms of effect in settings where disrespectful behavioural norms are proving to be resistant to change, as well as being a vehicle for ensuring that, once identified, any future local intervention can be designed to address and change these negative drivers.
There are many variations of the socio-ecological model in current circulation, applied to a wide range of disciplines and problems. What they all have in common is an understanding that human behaviour occurs in nested layers of the social systems in which people operate. The original model was proposed by Bronfenbrenner in 1977 [258] in the context of child development, with his final version being published in 1994 [259]. that are usually included in socio-ecological models (sometimes also categorised into 'micromeso-exo-macro' domains).
The model has an affinity with systems thinking and with complexity theory concepts of inter-connectivity, emergence, self-organisation and self-similarity at different levels of an organism or agency [260]. In other words, systems that are connected across some or all of these levels can tend to express similar characteristics in the component parts at each level. This is important in terms of understanding verbal and physical abuse in maternity care, as it is likely that attitudes, behaviours and norms that are apparent at lower levels of the system are modelled at higher levels of the system. Operating theories located in this review, such as gender norms, stigma and discrimination provide examples of this hypothesis.
Bronfenbrenner himself acknowledged that levels of the system operate in interaction with the people within them. His thinking moved from an emphasis on context towards an increasing recognition of the importance of recognising how far the individual (specifically the developing child, in his work) is in interplay with, and influences, that context. In this reading, the emergence of the cultures and norms, and, therefore the operation of each level of the socioecological system can be seen as a function of personal interaction, at least to some extent. This suggests that the analysis of and impacts on human behaviour at the individual/interpersonal level (as many implementation of change strategies are designed to do) misses critical human agency drivers and barriers at the meso-exo-macro level. This might limit the possibility of enacting change effectively, raising the hypothesis that understanding and influencing human behaviour at all levels of the system might be the key to change.
The family of theories that was most often evident in this review (either implicitly or explicitly) was one of the forms of the theory of planned behaviour. First published as the theory of Reasoned Action in 1980 [261] following an earlier paper setting the groundwork [262], the theory has undergone a series of transformations [263] as it has been refined to take into account psychological processes that human beings engage with as they decide whether or not to act in particular ways in specific circumstances. The labelling and composition of the model that results from the theory have varied over time, but the fundamental components relate to (perceived or actual) control over undertaking the behaviour; subjective and social norms (whether people that matter to the individual would approve, and whether the local social norms would support the action); and behavioural attitude (the extent to which performing the behaviour is perceived to be beneficial). The later formulations of the model add a level of intention to each of these three core components.
This iteration of the theory is detailed enough to capture both attitude and intent, while being simple enough to be interpreted in formative research. Implicitly or explicitly, many subsequent change models and theories encompass these concepts of, broadly, what is 'normal'/supported/enabled in the local context; what is easy for the individual to do; and what gives the individual a sense of benefit.
Despite the apparent utility of both systems and psychological theories in the context of health and social care, they have rarely been synthesised together. While socio-ecological theory is built on human/system interaction at the supra-individual level, this is usually in terms of the person experiencing the system (the child, patient, service user and so on) and not at the level of the people who are creating and sustaining it (staff, managers, policy makers, social influencers, for instance). In 2015 Nilsen identified around 40 frameworks, models and theories used in implementation science [264] most of which either have a primary focus on either systems/ environment, or on human factors. Few recognise that human factors influence all levels of the health and social care system. The assumption seems to be that either 'the system' is the issue, with resource limitations or availability and system constraints or freedoms forcing individuals to act in certain ways: or the individuals within the system are the drivers, having freewill to accept or resist institutional and social norms and expectations, including norms of stigma, stereotyping, and the range of theories of discrimination, othering, and exclusion identified in this review.
However, arguably, and as implied by Bronfenbrenner in his later outputs [259], systems are people. Deciding which resources to allocate to ensuring staff are well trained and that services are well-staffed, or that training schools are available, or who has the right to access care, or any of a myriad of other system level barriers and facilitators, are all decisions made by individuals acting on the basis of what they believe to be normal/acceptable to those they value or who have power over them; who make a judgement about what is the most likely (easiest) action or set of actions for a positive outcome; and about the degree of control they have to enact that resource allocation, or to legislate for a certain kind of (non)-discrimination; or to use nudge techniques to create a certain new cultural norm, for instance.
This suggests that interventions that do not take account of both organisational, cultural and political pressures, and the psychological intentions of actors at all system levels (based on their prior prejudices, attitudes and beliefs) will not be able to enact effective shifts in behaviours across the socio-ecological levels. In terms of respectful care, we have modelled this assumption in Fig 10, using examples of some of the explicit or implicit theories located in the review. This is not an exhaustive exercise-the intent is to show that at least some of the theories identified in the review could be mapped to all levels of the model.

Mapping the synthesis to maternity care interventions
We only located two controlled intervention studies in maternity care, published (in three papers [14, 15, 265] since our systematic review of the effectiveness of interventions to increase respectful care in 2018 [9]. The Asefa study [14,15] was before and after, was reported in 2020, and was undertaken in three hospitals in Ethiopia. The intervention was based on a multicomponent programme, including training of service providers, putting posters about the right to respectful care in labour rooms, and post-training quality improvement visits. It included measures of physical restraint and of gagging, both of which were reduced by the intervention, though the reduction did not reach statistical significance.
The study undertaken by Mihret [265] was also a before and after study, undertaken in 2020 in one hospital in Ethiopia. It was a multicomponent intervention, focused on both the antenatal and intrapartum period. The authors reported large differences between pre and post study measures, in overall disrespect and abuse, and in physical abuse specifically.
Putting these studies alongside the five studies (six papers) included in the Downe review [266][267][268][269][270][271] results in seven intervention studies, all undertaken in hospitals in either Ethiopia or Tanzania. Study characteristics and explicit/implicit underlying theories are given in Table 6.
In general, maternity studies in this area have included multi-component interventions, at various levels of the maternity care system, based on prior development work with key stakeholders. All the included studies report improvements in at least some of their outcomes. The one study that was largely focused on educational interventions alone reduced rates of episiotomy, but did not have a significant effect on overall verbal or physical abuse [266] To assess the extent to which the theories, models or approaches referenced might fit with the socio-ecological-behavioural approach proposed in our synthesis, we broadly aligned the intervention components described in the studies to both the socio-ecological and the behavioural elements (Table 7).
This exercise demonstrates that the components of the proposed socio-ecological-behavioural approach can account for interventions that have been tested, with some success, in the maternity setting in low-income countries. It also demonstrates, however, that most  interventions in the maternity field are focused on the personal, interpersonal and community/organisation level of the socio-ecological model, and on the normative and behavioural benefit components of behavioural change. At least in the published accounts we located, there appears to be less evidence of interventions targeted at the policy and cultural system level, though community and staff engagement was apparent in some of the included studies. Including these aspects more systematically in future interventions may impact on longer term sustainability, and the potential for a successful roll-out. Unlike the non-maternity studies, some of the controlled maternity studies do address verbal abuse. However, even where this is done, there does not seem to be strong evidence of effectiveness in reducing such abuse in most cases (see Table 6).

Observations on critical contexts and mechanisms of effect
This review describes the large spectrum of theories and models that have been used to explain the occurrence of verbal and physical abuse from health and social care staff towards those to whom they are providing care. Beyond these disparate theories, however, there appear to be two distinct contextual features across the range of included papers that appear to be associated with verbal and physical abuse, and that, we hypothesise, could map across the proposed socio-ecological-behavioural model. These are described in the logic model in Fig 11. In critical realist theory, mechanisms have been conceptualised as phenomena which, when triggered by specific contexts, produce specific outcomes through the resources and reasoning they generate [272]. They can catalyse 'demi-regularities' or similar outcomes, when similar contexts operate in different settings. We hypothesise that the two contextual features that emerged from a number of the studies we included may trigger 'mechanisms of effect' for Table 7. Mapping published studies of respectful care interventions in maternity services to the proposed socio-ecological-behavioural approach.

Behavioural beliefs Normative beliefs Control beliefs
Culture (macro level) Kujawski [267] Abuya [270] Kujawski [267] Abuya [270] ? Kujawski [267] ? Abuya [270] Policy (government level) verbal and physical abuse. These mechanisms could be discrimination, intersectional victimisation, stereotyping, bias, burnout, moral distress, or any of the other theoretical explanations described in the included studies. The first context is captured in the 'normalisation' theories logged against a number of studies in the review. The hypothesis is that behavioural intentions, attitudes, and actions (mechanisms) of discrimination, 'othering', staff burnout and etc; are triggered in contexts where violence is normalised across all levels of the socio-ecological system. The relevant contexts are those where violence is an everyday, and even trivial, 'fact of life', to the extent that it becomes expected, invisible, and, therefore, structurally embedded. Service users expect it, and report that they 'deserve' it, or that it is necessary for them to be abused, to ensure they are 'safe' (in psychiatric care) or that their baby is born 'safely'. Professionals expect to carry it out, and their organisations do not see such violence as requiring disciplinary action-indeed, if there is an adverse event and physical or verbal pressure has not been applied, organisations may hold the practitioner to account. Local communities anticipate that physical and verbal violence will be required when they attend health care settings, not least because such behaviour is normalised in general social interactions, especially in terms of violence towards women and people in other minoritized and stigmatised groups. This can be particularly evident for those experiencing intersectional marginalisation.
The second context intersects with the first. This is where there is a belief that physical or verbal mistreatment is necessary to minimise clinical harm. These are contexts where physical and verbal mistreatment are justified as being in the interests of the service user (or, in maternity care, the mother and/or baby) because they are believed to reduce particular physical harms, even when there is no evidence of such benefits, and even if the mistreatment might result in emotional and/or psychological harm. Selective use of this approach can be based on the belief that people with certain characteristics are more at risk of physical harm or less able or willing to take care of themselves, or (in the case of maternity care, or restraint use in ITU/ emergency departments) the belief that routine use of restrictive interventions is necessary to ensure 'safety' as measured by specific clinical outcomes.
This second context is paradoxical, since in most settings (including critical care, psychiatric nursing and maternity care) there is no evidence that verbal or physical violence or restraint improves clinical outcomes, and their use can be associated with iatrogenic harm. Indeed, in papers included in this review, some staff experience moral distress as a consequence of the dissonance between peer, organisational and societal imperatives to act with violence or physical restraint to reduce physical risk, and their professional identity as someone who has a compassionate duty to prevent emotional and psychological harm to their patients. As is evident in several of the included studies, one consequent outcome is that some staff will leave, creating increased staffing pressures for those who stay. Others stay in practice, but burn out, becoming increasingly indifferent to the use of physical and verbal abuse, and thus reinforcing the behavioural and contextual norms for such abuse, at all levels of the socio-ecological model.

Potential of the behavioural change wheel for design of future intervention studies
While the integrated socio-ecological behavioural approach proposed in this paper explains many of the findings in the review, it does not provide an analytic tool for intervention design. In 2011, Michie and colleagues published a paper introducing the Behavioural Change Wheel (BCW) [273,274]. The widely used COM-B behavioural change model, is at the heart of the BCW. The core drivers of behaviour in the COM-B model (Capability, Opportunity, and Motivation) have some synergy with the constructs of control beliefs, normative beliefs, and behavioural beliefs in the Theory of Planned Behaviour. However, the full BCW, as illustrated in Fig 12, also includes proposed drivers and techniques for addressing each of these behavioural drivers.
The BCW does not explicitly address all levels of the system, and it is relatively silent on the potential reciprocity between and within change at different system levels. Along with other behavioural change and implementation models, it has tended to be used to address welldefined practical changes that are not based on deep-seated values and norms (sitting behaviour, diet, handwashing, conversations about physical activity, for instance). The long-term sustainability of behavioural change following the use of such tools has not yet been widely assessed. This is important for the current review since the 'othering' that was identified in this study is a complex and deeply entrenched, often cross-generational social and behavioural norm, that requires a complete shift in individual, institutional, social and community beliefs and attitudes to ensure sustainable change. It remains to be seen if the new theoretical and practical behavioural tools can get beyond performative change in specific behaviours while the individuals concerned are under scrutiny, and ensure sustainable change in attitudes, beliefs and behaviours into the longer term. Despite these potential limitations, the BCW could provide a framework for developing a logic model for a multi-component intervention across the socio-ecological system to drive behavioural change in relation to normative violence against 'othered' groups in maternity care, and to remove the social acceptability of verbal and physical abuse as a means of optimising clinical maternal and neonatal outcomes.

Discussion
Our search for studies that have used a theoretical lens in the area of verbal and physical abuse found a large body of knowledge across multiple health settings, using a range of theories that could be captured by both the socio-ecological model, and the theory of planned behaviour. Most of the maternity care papers that incorporated some kind of implicit or explicit theory were undertaken in low and middle-income countries. This was also true for the maternity intervention studies assessed at the synthesis stage of the review. In contrast, in the other areas of health care represented, the vast majority were from high income settings, and notably from North America. This reflects the global emphasis on safe and respectful motherhood, particularly in low and middle-income countries, in contrast to specific concerns about physical restraint in a range of health and social care settings in high income countries, particularly in elderly and psychiatric settings.
Strikingly, we found very few non-maternity studies that addressed verbal abuse, and, even in the maternity studies, where this was more likely to be an outcome measure, there was little evidence of effect. The rise of on-line and remote health and social care delivery suggests that the risk of such mistreatment is likely to rise over the coming years. This is an important gap in the literature, both in general health and social care, and in maternity services.
Meta-analysing the included intervention studies to assess which approaches and theorybased interventions might be most likely to be effective was problematic, since the only measure that was common in the eligible intervention studies was physical restraint, and only 14 provided sufficient data for statistical analysis. Even though most of the individual studies claimed benefits for their interventions, the meta-analysis indicated there was overall little or marginal benefit for interventions used to date to reduce physical restraint. Only one study in the meta-analysis included either a theoretical approach, or an intervention focused on both staff and service users. Though these did appear to be more effective than other studies in the meta-analysis, this can only be the basis for hypothesis generation for future studies, given the paucity of evidence.
The theories and operational factors discussed in the included papers in both phases of the review covered all levels of the socio-ecological model, and are similar to those identified in other papers in the Series of which this review is a part [4,5]. The theories identified operated at the individual level (e.g. patient characteristics, staff stress/workload) the facility level (eg staff turnover, staffing levels, institutional culture), the level of policy (risk averse policies, resources and funding); and societal levels (gender inequality, marginalisation, stigma, and etc). Female gender inequality, and stereotyping, stigma and prejudice (involving immigrants, ethnic minorities, those of lower economic status, for instance) were noted as being influential and intersectional in many of the included studies/reviews.
Determining how to tackle complex multi-system problems (so called 'wicked' problems [275]) can seem to be an overwhelming task. Trying to resolve such complexity can lead to a sense of helplessness, and a retreat from the attempt, especially when many have tried before without success. It is for this reason that we are proposing an integration of the theory of planned behaviour with socio-ecological theory as one route to reducing verbal and physical abuse.
We are not proposing to add to the myriad of models and approaches for implementation of change that already exist. Some of these models and approaches are targeted on the index individuals in whom behavioural change is sought [264]. However, many do not include individuals at management, policy, funder and government level who have the potential power to change aspects of the socio-ecological system that could impact on behavioural change in the index individuals. Existing models could, though, be applied to such individuals in theory, if they were integrated with the socio-ecological model. The Behavioural Change Wheel [273], of which COM-B is a component, could be a useful starting point for the design of an intervention along these lines. Whatever model, theory or approach is used, it is important to note that complex systems are not complicated. They have simple rules [276]. Complicated theoretical models are therefore unlikely to be effective. We hypothesise that the two simple rules that underpin our proposed model are that to be effective and sustained, change must be fractal, across the whole of the relevant socio-ecological system: and that such sustained change depends on synergy between the beliefs, attitudes and norms of human actors at each level of the relevant system. Applying a context/mechanism/outcome lens to the data suggest that two contextual factors could be critical in sustaining the mechanisms that underpin the outcome of verbal and physical abuse in health and social care from both the socio-ecological and the behavioural perspective: namely, social normalisation of violence, particularly for 'othered' groups, and the belief that physical or verbal mistreatment is necessary to minimise clinical harm.
We suggest that one way of understanding and then addressing the issue of verbal and physical mistreatment in specific maternity care systems in future is to work with local stakeholders (staff, managers, community, service users, policy makers) to establish the extent to which the 'simple rules', contextual drivers and theories of discrimination and stereotyping revealed in this paper, and in the other papers in the Series [4,5] explain verbal and physical abuse locally. This mapping exercise should be done at every level of the local socio-ecological system, using the proposed socio-ecological-behavioural approach, alongside an existing compatible model, such as the Behavioural Change Wheel [274]. Only once this mapping, consultation or co-production, and analysis is done should the intervention be designed and then tested. This should involve stakeholders in considering how the identified drivers could be mapped to processes designed to be effective in changing the contexts that trigger harmful attitudes, norms and beliefs of the key actors at each level of that particular social system, including senior management, the local community, and political stakeholders. Consequent reductions in the harms caused by verbal and physical abuse could go beyond particular maternity care institutions, potentially improving the wellbeing of communities and staff, as well as service users.
In addition to improving the design and delivery of programmes, there is an urgent need to make sure that studies that do take place in future in this area capture outcomes consistently, both to allow for inter-study comparisons, and to optimise rapid learning and implementation of what works.

Limitations
We could not be sure that we located all the studies that could be relevant to the question as the topic area was broad. We did not include all the physical restraint studies we originally identified, due to the very large numbers of such studies, but we did include all the intervention studies designed to reduce unnecessary physical restraint, apart from any we could have missed due to translation issues. Our search and selection criteria were rigorous, and we do not believe that any studies that we missed would change our conclusions significantly.
We did not locate any controlled studies designed to address verbal abuse as a primary outcome. This an area that is in urgent need of addressing, especially as social media and remote provision of care provides a new space in which verbal abuse could be a primary focus for distress for pregnant and postnatal women and birthing people.
We were only able to meta-analyse studies that reported on physical restraint, as this was the only outcome that was both common to a large percentage of the study data set, and that was reported with data that could be meta-analysed. This resulted in an analysis that was heavily skewed towards high income countries, as physical restraint in elderly and mental health facilities is a topic of interest in these settings. It may also be seen to be somewhat removed from the kinds of maternity care mistreatment and abuse that are often reported. However, one maternity intervention paper we located did include measures of restraint and gagging in the Ethiopian context [15] and found a base rate of about 10% in each case, with a non-significant reduction to about 5%. This suggests that physical restraint is an important part of mistreatment in some maternity contexts, and that learning from studies that have tried to address it is important, even if they are undertaken in other health and social care areas, and in high income contexts.

Conclusions
Despite the interest in mistreatment in maternity care specifically and in health and social care more generally, there are still few intervention studies that are robust enough to be meta-analysed, and with outcomes that are consistent enough to be compared. Most non-maternity controlled studies are focused on physical restraint in elderly care and in psychiatric settings, suggesting that other areas of physical abuse, and the adverse effects of verbal abuse, have not yet been widely recognised. There is little evidence that controlled studies have been based on interventions and outcomes that take account of theoretical analysis of causation, despite the very wide and rich range of theories that have been suggested to have utility in this field. Intervention studies in maternity care seem to be more likely than those in other settings to take account of both systems level and behavioural factors in their intervention design, though with less emphasis on wider cultural and policy levels of the socio-ecological model than on those of the individual or the organisation.
Our findings suggest that the ethos and therefore the expression of D&A at each level of the system is moderated by the individuals who enact the system, and by what they feel they can control, what is socially normal, and what ultimately benefits them in that particular social context. In maternity care, systematic and routine disrespect and abuse of some women, carried out, condoned, or ignored by people operating in social groups at all system levels indicates that 'othering' of those with specific characteristics (depending on the particular social context) is (made) easy, normal and beneficial for individuals. In line with both the socio-ecological model, and the Theory of Planned Behaviour, our findings suggest that the solution is not to focus only on staff failure through systems level interventions (for example, through guidelines or training or audit, set up by the institution and targeted at particular behaviours of front line professionals). This may be part of the solution, but strategies based narrowly on such interventions risk being short-term, and only effective for the particular behaviours being targeted. The ultimate aim is to encourage sustainable changes in attitudes and beliefs that then permanently change a range of behaviours in individuals at all levels of the socio-ecological system, including senior staff and middle managers who set the organizational tone, politicians, organizational funders and auditors, leaders of local communities, front-line staff, and other key stakeholders. The intention is that resulting individual, group, institutional, and community norms change profoundly and sustainably to resist 'othering' at a fundamental level, and into the longer term, after the formal intervention programme is complete.
Using the complexity theory concept of 'simple rules' to address change in complex systems implies that approaches used in this field do not need to be complicated, as long as they address the simple rules of addressing socio-ecological system factors at all levels; and of influencing the attitudes and beliefs of the individuals who create these system factors, at all levels. This work needs to focus of societal normalisation of violence, particularly for 'othered' groups, and the belief that physical or verbal mistreatment is necessary to minimise clinical harm no matter what the cost for emotional and psychological wellbeing, It is important to combine an analysis of these factors in intervention design with local stakeholders, ideally in co-production models. Theoretically informed tools that integrate practical solutions, such as the Behavioural Change Wheel, might be helpful in designing such tailored interventions. Framing interventions that are locally determined, but which can 'read across' between studies, based on simple rules and realist demi-regularities is likely to maximise rapid learning between studies.
Supporting information S1